Oral care compositions comprising tin ions

ABSTRACT

An oral care composition with a tin, polyol with five or six carbon atoms, polyol with seven or more hydroxyl functional groups, and a pH of greater than 7. An oral care composition with a tin ion source, a fluoride ion source, a polyol with five or six carbon atoms, a non reducing sugar or sugar alcohol with seven or more hydroxyl functional groups, and a pH of greater than 7. Oral care compositions with a high tin ion availability.

FIELD OF THE INVENTION

The present invention relates to compositions comprising tin, polyolwith five or six carbon atoms, and polyol with seven or greater hydroxylfunctional groups at a pH of greater than 7. The present invention alsorelates to oral care compositions comprising stannous fluoride,stabilizing polyol, and gum strengthening polyol at a pH of greater than7.

BACKGROUND OF THE INVENTION

Sources of tin ions, such as stannous fluoride, are added to dentifricecompositions to deliver antimicrobial and antisensitivity benefits.However, tin ion sources can be difficult to incorporate into dentifricecompositions due to (i) the reactivity between tin ions and otherdentifrice components, such as silica, and (ii) the formation ofinsoluble tin compounds at particular pH conditions. Thus, theincorporation of tin ions into dentifrice compositions is only possibleby minimizing interactions between tin ions and key dentifricecomponents during storage to maximize tin ion availability forreactivity with oral cavity surfaces, such as enamel, dentine, gums,plaque, and bacteria.

The chemical instability in solution of tin ions can be mitigated bylowering the pH of the solution, providing anionic chelants, such asanions of organic acids, or providing polymeric chelants, such aspolyphosphates or polycarboxylates. Some of these chelants can alsoprevent tin ion interactions with the surface of silica molecules bybinding directly to the tin ions. However, strong chelant-tin ioninteractions can also be detrimental to tin ion availability if thechelant-tin ion interactions are stronger than binding affinity betweentin ions and intra oral surfaces, such tin ion delivery is aprerequisite for performance against diseases of the oral cavity such asplaque, gingivitis, malodor, caries, sensitivity, and dental erosionetc. Thus, even chelant selection must be balanced with the overalldentifrice formulation to maximize tin ion availability.

Due to the chemical instability of tin ions in aqueous-based dentifricecompositions, stannous fluoride is not typically used in aqueouscompositions without the use of chelants, such as gluconate or citrate.Moreover, high pH aqueous dentifrice compositions are even lesspreferred due to the potential formation of Sn(OH)₂, which canprecipitate out of the dentifrice composition at a pH of greater than 7.Anhydrous conditions can be used to formulate stable compositions withstannous fluoride. Polyols, such as glycerin, sorbitol, and xylitol canbe added to anhydrous dentifrice compositions as a replacement carriermaterial in place of water. However, polyols can be expensive relativeto other carrier materials in water-based dentifrice compositions.Accordingly, there is a need for a stable, water-based dentifricecomposition that does not require chelants, which can be detrimental tothe tin ion availability in the dentifrice composition.

SUMMARY OF THE INVENTION

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the detaileddescription. This summary is not intended to identify required oressential features of the claimed subject matter. Nor is this summaryintended to be used to limit the scope of the claimed subject matter.

Disclosed herein is an oral care composition comprising (a) from about0.0025% to about 5%, by weight of the oral care composition, of a tinion source; (b) from about 5% to about 50%, by weight of the oral carecomposition, of a stabilizing polyol having from five or six carbonatoms; (c) from about 0.0025% to about 20%, by weight of the oral carecomposition, of a gum strengthening polyolpolyol having seven or morehydroxyl functional groups, and (d) up to about 45%, by weight of theoral care composition, of water, wherein the oral care composition has apH of greater than 7.

Disclosed herein is an oral care composition comprising (a) from about0.0025% to about 5%, by weight of the oral care composition, of a tinion source; (b) from about 5% to about 50%, by weight of the oral carecomposition, of a stabilizing polyol having from five or six carbonatoms; (c) from about 0.0025% to about 20%, by weight of the oral carecomposition, of a gum polyol having seven or more hydroxyl functionalgroups, and (d) from about 45% to about 75%, by weight of the oral carecomposition, of water, wherein the oral care composition has a pH ofgreater than 7.

Disclosed herein is an oral care composition comprising (a) from about0.0025% to about 5%, by weight of the oral care composition, of a tinion source, (b) from about 0.0025% to about 5%, by weight of the oralcare composition, of a fluoride ion source, the fluoride ion sourcecomprising sodium fluoride, sodium monofluorophosphate, amine fluoride,or combinations thereof, (c) from about 5% to about 50%, by weight ofthe oral care composition, of a stabilizing polyol having from five orsix carbon atoms; (d) from about 0.0025% to about 20%, by weight of theoral care composition, of a gum strengthening polyol having seven ormore hydroxyl functional groups, and (e) from about 10% to about 45%, byweight of the oral care composition, of water, wherein the oral carecomposition has a pH of greater than 7.

Disclosed herein is an oral care composition comprising (a) from about0.0025% to about 5%, by weight of the oral care composition, of a tinion source, (b) from about 5% to about 50%, by weight of the oral carecomposition, of a stabilizing polyol having five or six carbon atoms;(c) from about 0.0025% to about 20%, by weight of the oral carecomposition, of a gum strengthening polyol having seven or more hydroxylfunctional groups, and (d) from about 75% to about 99%, by weight of thecomposition, of water, wherein the oral composition has a pH of greaterthan 7.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an illustration of the solubilization of tin ions at variouspH conditions with sorbitol.

FIG. 2 is an illustration of the solubilization of tin ions at variouspH conditions with trehalose.

FIG. 3 is an illustration of the solubilization of tin ions at variouspH conditions with isomalt.

FIG. 4 is an illustration of the solubilization of tin ions at variouspH conditions with trehalose and sorbitol at a 1:1 ratio.

FIG. 5 is an illustration of the solubilization of tin ions at variouspH conditions with trehalose and sorbitol at a 3:1 ratio.

FIG. 6 is an illustration of the solubilization of tin ions at variouspH conditions with isomalt and sorbitol at a 1:1 ratio.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to oral care compositions comprising atin ion source, a polyol with five or six carbon atoms, and a polyolwith seven or more carbon atoms at a pH of greater than 7 or from about7.5 to about 10.

Tin ion sources are not typically used in aqueous dentifricecompositions at a pH of greater than 7 due to the formation of Sn(OH)₂,which can precipitate out of the dentifrice composition immediately uponmixing or while the dentifrice composition is stored prior to use by aconsumer, thereby eliminating any benefit derived from free tin ions.

As such, aqueous dentifrice compositions comprising a tin ion source ata pH of greater than 7 are typically not expected to be compatible.Unexpectedly, and as described herein, stable dentifrice compositionscomprising a tin ion source and a polyol with five or more atoms at a pHof greater than 7 have been found to be shelf stable with minimal or noformation of Sn(OH)₂. Without wishing to be bound by theory, it isbelieved that when dentifrice compositions comprising a tin ion sourceand a polyol with five or more carbon atoms are properly formulated, thepolyol with five or more carbon atoms can weakly interact with the freetin ions to prevent the formation of insoluble Sn(OH)₂ at elevated pHconditions.

In regard to the highly specified cell-to-cell junctions and highrenewal capabilities, gingival epithelium is considered a strong butpassive barrier and is constantly exposed to environmental stimulationby (i) the rich and diverse tooth adherent microbiome and bacterialchallenges and (ii) the continuous barrier damage arising from chewingand hygiene regimens.

The gingival epithelial cells are one of the first host cell types thatare in constant contact with bacterial products. Loss of epithelialintegrity, barrier and disruption has been associated with invasion ofbacteria into underlying connective tissues, potentially increasing theinflammatory response and the subsequent tissue damage, characteristicof gingivitis and periodontal disease.

Unexpectedly, and as described herein, polyols with seven or morehydroxyl functional groups can additionally lead to an improvement inthe barrier function of epithelial surfaces found in the oral cavity.While polyols with seven or more hydroxyl functional groups can (i)stabilize tin ions and/or (ii) improve the barrier function ofepithelial surfaces found in the oral cavity, polyols with seven or morehydroxyl functional groups can be cost prohibitive when added to oralcare compositions in the needed amounts. Thus, the present invention isalso directed to oral care compositions with a tin ion source, astabilizing polyol having five or six carbon atoms, and a gum polyolwith seven or more hydroxyl functional groups.

While the specification concludes with claims particularly pointing outand distinctly claiming the invention, it is believed that the presentinvention will be better understood from the following description.

Definitions

To define more clearly the terms used herein, the following definitionsare provided. Unless otherwise indicated, the following definitions areapplicable to this disclosure. If a term is used in this disclosure butis not specifically defined herein, the definition from the IUPACCompendium of Chemical Terminology, 2nd Ed (1997), can be applied, aslong as that definition does not conflict with any other disclosure ordefinition applied herein, or render indefinite or non-enabled any claimto which that definition is applied.

The term “oral care composition”, as used herein, includes a product,which in the ordinary course of usage, is not intentionally swallowedfor purposes of systemic administration of particular therapeuticagents, but is rather retained in the oral cavity for a time sufficientto contact dental surfaces or oral tissues. Examples of oral carecompositions include dentifrice, tooth gel, subgingival gel, mouthrinse, mousse, foam, mouth spray, lozenge, chewable tablet, chewing gum,tooth whitening strips, floss and floss coatings, breath fresheningdissolvable strips, or denture care or adhesive product. The oral carecomposition may also be incorporated onto strips or films for directapplication or attachment to oral surfaces.

The term “dentifrice composition”, as used herein, includes tooth orsubgingival-paste, gel, or liquid formulations unless otherwisespecified. The dentifrice composition may be a single-phase compositionor may be a combination of two or more separate dentifrice compositions.The dentifrice composition may be in any desired form, such as deepstriped, surface striped, multilayered, having a gel surrounding apaste, or any combination thereof. Each dentifrice composition in adentifrice comprising two or more separate dentifrice compositions maybe contained in a physically separated compartment of a dispenser anddispensed side-by-side.

“Active and other ingredients” useful herein may be categorized ordescribed herein by their cosmetic and/or therapeutic benefit or theirpostulated mode of action or function. However, it is to be understoodthat the active and other ingredients useful herein can, in someinstances, provide more than one cosmetic and/or therapeutic benefit orfunction or operate via more than one mode of action. Therefore,classifications herein are made for the sake of convenience and are notintended to limit an ingredient to the particularly stated function(s)or activities listed.

The term “orally acceptable carrier” comprises one or more compatiblesolid or liquid excipients or diluents which are suitable for topicaloral administration. By “compatible,” as used herein, is meant that thecomponents of the composition are capable of being commingled withoutinteraction in a manner which would substantially reduce thecomposition's stability and/or efficacy. The carriers or excipients ofthe present invention can include the usual and conventional componentsof mouthwashes or mouth rinses, as more fully described hereinafter:Mouthwash or mouth rinse carrier materials typically include, but arenot limited to one or more of water, alcohol, humectants, surfactants,and acceptance improving agents, such as flavoring, sweetening, coloringand/or cooling agents.

The term “substantially free” as used herein refers to the presence ofno more than 0.05%, preferably no more than 0.01%, and more preferablyno more than 0.001%, of an indicated material in a composition, by totalweight of such composition.

The term “essentially free” as used herein means that the indicatedmaterial is not deliberately added to the composition, or preferably notpresent at analytically detectable levels. It is meant to includecompositions whereby the indicated material is present only as animpurity of one of the other materials deliberately added.

While compositions and methods are described herein in terms of“comprising” various components or steps, the compositions and methodscan also “consist essentially of” or “consist of” the various componentsor steps, unless stated otherwise.

As used herein, the word “or” when used as a connector of two or moreelements is meant to include the elements individually and incombination; for example, X or Y, means X or Y or both.

As used herein, the articles “a” and “an” are understood to mean one ormore of the material that is claimed or described, for example, “an oralcare composition” or “a bleaching agent.”

All measurements referred to herein are made at about 23° C. (i.e. roomtemperature) unless otherwise specified.

Generally, groups of elements are indicated using the numbering schemeindicated in the version of the periodic table of elements published inChemical and Engineering News, 63(5), 27, 1985. In some instances, agroup of elements can be indicated using a common name assigned to thegroup; for example, alkali metals for Group 1 elements, alkaline earthmetals for Group 2 elements, and so forth.

Several types of ranges are disclosed in the present invention. When arange of any type is disclosed or claimed, the intent is to disclose orclaim individually each possible number that such a range couldreasonably encompass, including end points of the range as well as anysub-ranges and combinations of sub-ranges encompassed therein.

The term “about” means that amounts, sizes, formulations, parameters,and other quantities and characteristics are not and need not be exact,but can be approximate and/or larger or smaller, as desired, reflectingtolerances, conversion factors, rounding off, measurement errors, andthe like, and other factors known to those of skill in the art. Ingeneral, an amount, size, formulation, parameter or other quantity orcharacteristic is “about” or “approximate” whether or not expresslystated to be such. The term “about” also encompasses amounts that differdue to different equilibrium conditions for a composition resulting froma particular initial mixture. Whether or not modified by the term“about,” the claims include equivalents to the quantities. The term“about” can mean within 10% of the reported numerical value, preferablywithin 5% of the reported numerical value.

The dentifrice composition can be in any suitable form, such as a solid,liquid, powder, paste, or combinations thereof. The oral carecomposition can be dentifrice, tooth gel, subgingival gel, mouth rinse,mousse, foam, mouth spray, lozenge, chewable tablet, chewing gum, toothwhitening strips, floss and floss coatings, breath fresheningdissolvable strips, or denture care or adhesive product. The componentsof the dentifrice composition can be incorporated into a film, a strip,a foam, or a fiber-based dentifrice composition. The dentifricecomposition can include a variety of active and inactive ingredients,such as, for example, but not limited to a tin ion source, a stabilizingpolyol, a gum strengthening polyol, an abrasive, water, a fluoride ionsource, zinc ion source, one or more polyphosphates, additionalhumectants, surfactants, other ingredients, and the like, as well as anycombination thereof, as described below.

Tin

The oral care compositions of the present invention comprise tin. Thetin can be provided by a tin ion source. The tin ion source can be anysuitable compound that can provide tin ions in an oral care compositionand/or deliver tin ions to the oral cavity when the dentifricecomposition is applied to the oral cavity. The tin ion source cancomprise one or more tin containing compounds, such as stannousfluoride, stannous chloride, stannous bromide, stannous iodide, stannousoxide, stannous sulfate, stannous sulfide, stannic fluoride, stannicchloride, stannic bromide, stannic iodide, stannic sulfide, and/ormixtures thereof. Preferably, the tin ion source can comprise stannousfluoride, stannous chloride, and/or mixture thereof.

The oral care compositions can comprise from about 0.0025% to about 5%,from about 0.2% to about 1%, from about 0.5% to about 1.5%, or fromabout 0.3% to about 0.6%, by weight of the oral care composition, of atin ion source.

Stabilizing Polyol

The oral care compositions of the present invention comprise one or morestabilizing polyols. A polyol is an organic compound with more than onehydroxyl functional groups. The stabilizing polyol can be any suitablepolyol that can weakly associate, interact, or bond to tin ions whilethe oral care composition is stored prior to use. The stabilizing polyolcan be a sugar alcohol, a monosaccharide, a disaccharide, apolysaccharide, or a non-reducing sugar. Sugar alcohols are a class ofpolyols that can be obtained through the hydrogenation of sugarcompounds with the formula (CHOH)_(n)H₂, where n=4-6. Preferably, n is 5and/or 6 because these compounds have been shown to unexpectedlyinteract with tin ion sources to create soluble complexes, as describedherein, at a reasonable formulation cost. Non-reducing sugars are aclass of saccharides that do not generate any compounds containing analdehyde functional group. Non-reducing sugars are stable in water anddo not react with weak oxidizing agents to produce sugar alcohols.Examples of suitable non-reducing sugars include, but are not limitedto, sucrose, trehalose, raffinose, stachyose, verbascose, orcombinbations thereof. Preferably, the stabilizing polyol is a sugaralcohol.

The stabilizing polyol can be xylitol, sorbitol, mannitol, lactitol,galactitol, isomalt, and/or combinations thereof. Preferably, thestabilizing polyol can be a sugar alcohol with the formula (CHOH)_(n)H₂,where n=5 and/or 6. More preferably, the stabilizing polyol can bexylitol, sorbitol, galactitol, and/or mixtures thereof.

The oral care composition can comprise 0.01% to about 70%, from about 5%to about 70%, from about 5% to about 50%, from about 10% to about 60%,or from about 20% to about 80%, by weight of the oral care composition,of a stabilizing polyol.

The oral care composition can also comprise an additional humectant,have low levels of an additional humectant, or be free of an additionalhumectant. Humectants, in general, serve to add body or “mouth texture”to an oral care composition or dentifrice as well as preventing the oralcare composition from drying out. Suitable humectants includepolyethylene glycol (at a variety of different molecular weights),propylene glycol, glycerin, erythritol, xylitol, sorbitol, mannitol,butylene glycol, lactitol, hydrogenated starch hydrolysates, and/ormixtures thereof. The oral care composition can comprise a polyol and anadditional humectant, such as xylitol to interact with the tin ionsource and glycerin to prevent the oral care composition from drying outduring storage or add body to the oral care composition. The oral carecomposition can also be free of an additional humectant because thepolyol can serve as both the polyol and the additional humectant, suchas when the polyol is xylitol, sorbitol, or combinations thereof.

The oral care composition can comprise one or more humectants each at alevel of from about 0.01% to about 70%, from about 5% to about 50%, fromabout 10% to about 60%, or from about 20% to about 80%, by weight of theoral care composition.

Gum Strengthening Polyol

The oral care compositions of the present invention comprise one or moregum strengthening polyols. While polyols with five or more carbon atomshave been shown to stabilize tin ions, polyols with seven or morehydroxyl functional groups have been shown to additionally strengthenthe barrier function of epithelial cells in the oral cavity. Whilepolyols with seven or more hydroxyl functional groups can be costprohibitive, as described herein, a combination of a polyol with five orsix carbon atoms (the “stabilizing polyol”) with a polyol with seven ormore hydroxyl functional groups (the “gum strengthening polyol”) canprovide a similar benefit with a reasonable cost.

The gum strengthening polyol can be a sugar alcohol, a monosaccharide, adisaccharide, a polysaccharide, or a non-reducing sugar. Sugar alcoholsare a class of polyols that can be obtained through the hydrogenation ofsugar compounds with the formula (CHOH)_(n)H₂, where n is seven or more,such as isomalt, maltitol, lactitol, maltotriitol, maltotetraitol,polyglycitol, or combinations thereof. Preferably, n is from about 7 toabout 12. Even more preferably, the gum strengthening polyol is isomalt,maltitol, lactitol, or combinations thereof.

Non-reducing sugars are a class of saccharides that do not generate anycompounds containing an aldehyde functional group. Non-reducing sugarsare stable in water and do not react with weak oxidizing agents toproduce sugar alcohols. Non-reducing sugars cannot donate electrons toother molecules, and is typically a di, tri, terta, penta saccharide,such as sucrose, trehalose, raffinose, stachyose, verbascose, orcombinbations thereof. Preferably, the gum strengthening polyol istrehalose. The gum barrier properties can be obtained from a combinationmixture of polyols whereby all have seven or greater hydroxyl functionalgroups.

The oral care composition can comprise 0.025% to about 20%, from about0.01% to about 15%, from about 1% to about 10%, from about 0.01% toabout 15%, or from about 0.0025% to about 10%, by weight of the oralcare composition, of a gum strengthening polyol.

Abrasive

The oral care composition of the present invention can compriseabrasive. Abrasives can be added to oral care formulations to helpremove surface stains from teeth. Preferably, the abrasive is a calciumabrasive or a silica abrasive.

The calcium abrasive can be any suitable abrasive compound that canprovide calcium ions in an oral care composition and/or deliver calciumions to the oral cavity when the oral care composition is applied to theoral cavity. The oral care composition can comprise from about 5% toabout 70%, from about 10% to about 60%, from about 20% to about 50%,from about 25% to about 40%, or from about 1% to about 50% of a calciumabrasive. The calcium abrasive can comprise one or more calcium abrasivecompounds, such as calcium carbonate, precipitated calcium carbonate(PCC), ground calcium carbonate (GCC), chalk, dicalcium phosphate,calcium pyrophosphate, and/or mixtures thereof.

The oral care composition can also comprise a silica abrasive, such assilica gel (by itself, and of any structure), precipitated silica,amorphous precipitated silica (by itself, and of any structure as well),hydrated silica, and/or combinations thereof. The oral care compositioncan comprise from about 5% to about 70%, from about 10% to about 60%,from about 10% to about 50%, from about 20% to about 50%, from about 25%to about 40%, or from about 1% to about 50% of a silica abrasive.

The oral care composition can also comprise another abrasive, such asbentonite, perlite, titanium dioxide, alumina, hydrated alumina,calcined alumina, aluminum silicate, insoluble sodium metaphosphate,insoluble potassium metaphosphate, insoluble magnesium carbonate,zirconium silicate, particulate thermosetting resins and other suitableabrasive materials. The oral care composition can comprise from about 5%to about 70%, from about 10% to about 60%, from about 10% to about 50%,from about 20% to about 50%, from about 25% to about 40%, or from about1% to about 50% of another abrasive.

Alternatively, the oral care composition can be substantially free of,essentially free of, or free of silica, alumina, or any othernon-calcium abrasive. The oral care composition can comprise less thanabout 5%, less than about 1%, less than about 0.5%, less than about0.1%, or 0% of a non-calcium abrasive, such as silica and/or alumina.

Water

The oral care composition of the present invention can be a dentifricecomposition that is anhydrous, a low water formulation, or a high waterformulation. In total, the oral care composition can comprise from 0% toabout 99%, about 20% or greater, about 30% or greater, about 50% orgreater, up to about 45%, or up to about 75%, by weight of thecomposition, of water. Preferably, the water is USP water.

In a high water dentifrice formulation, the dentifrice compositioncomprises from about 45% to about 75%, by weight of the composition, ofwater. The high water dentifrice composition can comprise from about 45%to about 65%, from about 45% to about 55%, or from about 46% to about54%, by weight of the composition, of water. The water may be added tothe high water dentifrice formulation and/or may come into thecomposition from the inclusion of other ingredients.

In a low water dentifrice formulation, the dentifrice compositioncomprises from about 10% to about 45%, by weight of the composition, ofwater. The low water dentifrice composition can comprise from about 10%to about 35%, from about 15% to about 25%, or from about 20% to about25%, by weight of the composition, of water. The water may be added tothe low water dentifrice formulation and/or may come into thecomposition from the inclusion of other ingredients.

In an anhydrous dentifrice formulation, the dentifrice compositioncomprises less than about 10%, by weight of the composition, of water.The anhydrous dentifrice composition comprises less than about 5%, lessthan about 1%, or 0%, by weight of the composition, of water. The watermay be added to the anhydrous formulation and/or may come into thedentifrice composition from the inclusion of other ingredients.

The dentifrice composition can also comprise other orally acceptablecarrier materials, such as alcohol, humectants, polymers, surfactants,and acceptance improving agents, such as flavoring, sweetening, coloringand/or cooling agents.

The oral care composition can also be a mouth rinse formulation. A mouthrinse formulation can comprise from about 75% to about 99%, from about75% to about 95%, or from about 80% to about 95% of water.

pH

The oral care composition can comprise one or more buffering agents.Buffering agents, as used herein, refer to agents that can be used toadjust the slurry pH of the oral care compositions to a range of greaterthan 7, from greater than 7 to about 14, about 7.5 or greater, about 8or greater, from about 7.5 to about 10, greater than 7 to about 10, fromabout 8 to about 10, from about 8 to about 9.5, or from about 8.5 toabout 9. The pH of a mouthrinse solution can be determined as the pH ofthe neat solution. The pH of a dentifrice composition can be determinedas a slurry pH, which is the pH of a mixture of the dentifricecomposition and water, such as a 1:4, 1:3, or 1:2 mixture of thedentifrice composition and water. The buffering agents include alkalimetal hydroxides, carbonates, sesquicarbonates, borates, silicates,phosphates, imidazole, and mixtures thereof. Specific buffering agentsinclude monosodium phosphate, trisodium phosphate, sodium hydroxide,potassium hydroxide, alkali metal carbonate salts, sodium carbonate,imidazole, pyrophosphate salts, citric acid, and sodium citrate. Theoral care composition can comprise one or more buffering agents each ata level of from about 0.1% to about 30%, from about 1% to about 10%, orfrom about 1.5% to about 3%, by weight of the present composition.

Zinc

The oral care composition can comprise zinc. The zinc can be provided bya zinc ion source. The zinc ion source can comprise one or more zinccontaining compounds, such as zinc fluoride, zinc lactate, zinc oxide,zinc phosphate, zinc chloride, zinc acetate, zinc hexafluorozirconate,zinc sulfate, zinc tartrate, zinc gluconate, zinc citrate, zinc malate,zinc glycinate, zinc pyrophosphate, zinc metaphosphate, zinc oxalate,and/or zinc carbonate.

The zinc ion source may be present in the total oral care composition atan amount of from about 0.01% to about 5%, from about 0.2% to about 1%,from about 0.5% to about 1.5%, or from about 0.3% to about 0.6%, byweight of the oral care composition.

Fluoride

The oral care composition can comprise fluoride. The fluoride can beprovided by a fluoride ion source. The fluoride ion source can compriseone or more fluoride containing compounds, such as stannous fluoride,sodium fluoride, potassium fluoride, amine fluoride, sodiummonofluorophosphate, zinc fluoride, and/or mixtures thereof.

The fluoride ion source and the tin ion source can be the same compound,such as for example, stannous fluoride, which can generate tin ions andfluoride ions. Additionally, the fluoride ion source and the tin ionsource can be separate compounds, such as when the tin ion source isstannous chloride and the fluoride ion source is sodiummonofluorophosphate or sodium fluoride.

The fluoride ion source and the zinc ion source can be the samecompound, such as for example, zinc fluoride, which can generate zincions and fluoride ions. Additionally, the fluoride ion source and thezinc ion source can be separate compounds, such as when the zinc ionsource is zinc phosphate and the fluoride ion source is stannousfluoride.

The oral care composition can comprise a fluoride ion source capable ofproviding from about 50 ppm to about 3500 ppm, and preferably from about500 ppm to about 3000 ppm of free fluoride ions. To deliver the desiredamount of fluoride ions, the fluoride ion source may be present in thetotal oral care composition at an amount of from about 0.0025% to about5%, from about 0.2% to about 1%, from about 0.5% to about 1.5%, or fromabout 0.3% to about 0.6%, by weight of the oral care composition.

Polyphosphates

The oral care composition can comprise polyphosphate. The polyphosphatecan be provided by a polyphosphate source. A polyphosphate source cancomprise one or more polyphosphate molecules. Polyphosphates are a classof materials obtained by the dehydration and condensation oforthophosphate to yield linear and cyclic polyphosphates of varyingchain lengths. Thus, polyphosphate molecules are generally identifiedwith an average number (n) of polyphosphate molecules, as describedbelow. A polyphosphate is generally understood to consist of two or morephosphate molecules arranged primarily in a linear configuration,although some cyclic derivatives may be present.

Preferred polyphosphates are those having an average of two or morephosphate groups so that surface adsorption at effective concentrationsproduces sufficient non-bound phosphate functions, which enhance theanionic surface charge as well as hydrophilic character of the surfaces.Preferred in this invention are the linear polyphosphates having theformula: XO(XPO₃)_(n)X, wherein X is sodium, potassium, ammonium, or anyother alkali metal cations and n averages from about 2 to about 21.Alkali earth metal cations, such as calcium, are not preferred becausethey tend to form insoluble fluoride salts from aqueous solutionscomprising a fluoride ions and alkali earth metal cations. Thus, theoral care compositions disclosed herein can be free of or substantiallyfree of calcium pyrophosphate.

Some examples of suitable polyphosphate molecules include, for example,pyrophosphate (n=2), tripolyphosphate (n=3), tetrapolyphosphate (n=4),sodaphos polyphosphate (n=6), hexaphos polyphosphate (n=13), benephospolyphosphate (n=14), hexametaphosphate (n=21), which is also known asGlass H. Polyphosphates can include those polyphosphate compoundsmanufactured by FMC Corporation, ICL Performance Products, and/orAstaris.

The oral care composition can comprise from about 0.01% to about 15%,from about 0.1% to about 10%, from about 0.5% to about 5%, from about 1to about 20%, or about 10% or less, by weight of the oral carecomposition, of the polyphosphate source.

Surfactants

The oral care composition can comprise one or more surfactants. Thesurfactants can be used to make the compositions more cosmeticallyacceptable. The surfactant is preferably a detersive material whichimparts to the composition detersive and foaming properties. Suitablesurfactants are safe and effective amounts of anionic, cationic,nonionic, zwitterionic, amphoteric and betaine surfactants, such assodium lauryl sulfate, sodium lauryl isethionate, sodium lauroyl methylisethionate, sodium cocoyl glutamate, sodium dodecyl benzene sulfonate,alkali metal or ammonium salts of lauroyl sarcosinate, myristoylsarcosinate, palmitoyl sarcosinate, stearoyl sarcosinate and oleoylsarcosinate, polyoxyethylene sorbitan monostearate, isostearate andlaurate, sodium lauryl sulfoacetate, N-lauroyl sarcosine, the sodium,potassium, and ethanolamine salts of N-lauroyl, N-myristoyl, orN-palmitoyl sarcosine, polyethylene oxide condensates of alkyl phenols,cocoamidopropyl betaine, lauramidopropyl betaine, palmityl betaine,sodium cocoyl glutamate, and the like. Sodium lauryl sulfate is apreferred surfactant. The oral care composition can comprise one or moresurfactants each at a level from about 0.01% to about 15%, from about0.3% to about 10%, or from about 0.3% to about 2.5%, by weight of theoral care composition.

Thickening Agents

The oral care composition can comprise one or more thickening agents.Thickening agents can be useful in the oral care compositions to providea gelatinous structure that stabilizes the toothpaste against phaseseparation. Suitable thickening agents include polysaccharides,polymers, and/or silica thickeners. Some non-limiting examples ofpolysaccharides include starch; glycerite of starch; gums such as gumkaraya (sterculia gum), gum tragacanth, gum arabic, gum ghatti, gumacacia, xanthan gum, guar gum and cellulose gum; magnesium aluminumsilicate (Veegum); carrageenan; sodium alginate; agar-agar pectin;gelatin; cellulose compounds such as cellulose, carboxymethyl cellulose,hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxymethylcellulose, hydroxymethyl carboxypropyl cellulose, methyl cellulose,ethyl cellulose, and sulfated cellulose; natural and synthetic clayssuch as hectorite clays; and mixtures thereof.

The thickening agent can comprise polysaccharides. Polysaccharides thatare suitable for use herein include carageenans, gellan gum, locust beangum, xanthan gum, carbomers, poloxamers, modified cellulose, andmixtures thereof. Carageenan is a polysaccharide derived from seaweed.There are several types of carageenan that may be distinguished by theirseaweed source and/or by their degree of and position of sulfation. Thethickening agent can comprise kappa carageenans, modified kappacarageenans, iota carageenans, modified iota carageenans, lambdacarrageenan, and mixtures thereof. Carageenans suitable for use hereininclude those commercially available from the FMC Company under theseries designation “Viscarin,” including but not limited to Viscarin TP329, Viscarin TP 388, and Viscarin TP 389.

The thickening agent can comprise one or more polymers. The polymer canbe a polyethylene glycol (PEG), a polyvinylpyrrolidone (PVP), apolyacrylic acid polymer, a polymer derived from at least one acrylicacid monomer, a copolymer of maleic anhydride and methyl vinyl ether, acrosslinked polyacrylic acid polymer, of various weight percentages ofthe oral care composition as well as various ranges of average molecularranges.

The thickening agent can comprise inorganic thickening agents. Somenon-limiting examples of suitable inorganic thickening agents includecolloidal magnesium aluminum silicate, silica thickeners. Useful silicathickeners include, for example, include, as a non-limiting example, anamorphous precipitated silica such as ZEODENT® 165 silica. Othernon-limiting silica thickeners include ZEODENT® 153, 163, and 167, andZEOFREE® 177 and 265 silica products, all available from EvonikCorporation, and AEROSIL® fumed silicas.

Preferably, the thicking agent can comprise at least one of a linearsulfated polysaccharide, a natural gum, a cellulose derivative, apolyacrylic acid polymer, or combinations thereof.

The oral care composition can comprise from 0.01% to about 15%, from0.1% to about 10%, from about 0.2% to about 5%, or from about 0.5% toabout 2% of one or more thickening agents.

Chelant

The oral care composition can comprise one or more chelants, having amolecular weight (MW) of less than 1000. The term “chelant”, as usedherein means a bi- or multidentate ligand having at least two groupscapable of binding to the divalent metal ions. Typically, those chelantsuseful herein will also form water soluble complexes with the stannousions. Oral care compositions comprising silica abrasives typicallyinclude one or more chelants to reversibly bind the tin ions to preventthe tin ions from irreversibly binding to the surface of silicaparticles. Suitable chelants herein include C₂-C₆ dicarboxylic andtricarboxylic acids, such as succinic acid, malic acid, tartaric acidand citric acid; C₃-C₆ monocarboxylic acids substituted with hydroxyl,such as gluconic acid; picolinic acid; amino acids such as glycine;phytic acid, salts thereof and mixtures thereof. Preferably, the chelantis sodium gluconate or a salt of citric acid.

The oral care composition can comprise one or more chelants each at alevel of from about 0.01% to about 5%, from about 0.2% to about 2%, fromabout 0.5% to about 1.5%, or from about 1% to about 3%, by weight of theoral care composition. Alternatively, the oral care composition can besubstantially free of, essentially free of, or free of a chelant becausethe oral care compositions of the present invention comprises a calciumabrasive instead of a silica abrasive. Additionally, the oral carecomposition can comprise one or more chelants each at a level of lessthan about 1%, less than about 0.5%, less than about 0.1%, or less thanabout 0.01%, by weight of the oral care composition.

Other Ingredients

The oral care composition can comprise a variety of other ingredients,such as flavoring agents, sweeteners, colorants, preservatives,buffering agents, or other ingredients suitable for use in oral carecompositions, as described below.

Flavoring agents also can be added to the oral care composition.Suitable flavoring agents include oil of wintergreen, oil of peppermint,oil of spearmint, clove bud oil, menthol, anethole, methyl salicylate,eucalyptol, cassia, 1-menthyl acetate, sage, eugenol, parsley oil,oxanone, alpha-irisone, marjoram, lemon, orange, propenyl guaethol,cinnamon, vanillin, ethyl vanillin, heliotropine, 4-cis-heptenal,diacetyl, methyl-para-tert-butyl phenyl acetate, and mixtures thereof.Coolants may also be part of the flavor system. Preferred coolants inthe present compositions are the paramenthan carboxyamide agents such asN-ethyl-p-menthan-3-carboxamide (known commercially as “WS-3”) orN-(Ethoxycarbonylmethyl)-3-p-menthanecarboxamide (known commercially as“WS-5”), and mixtures thereof. A flavor system is generally used in thecompositions at levels of from about 0.001% to about 5%, by weight ofthe oral care composition. These flavoring agents generally comprisemixtures of aldehydes, ketones, esters, phenols, acids, and aliphatic,aromatic and other alcohols.

Sweeteners can be added to the oral care composition to impart apleasing taste to the product. Suitable sweeteners include saccharin (assodium, potassium or calcium saccharin), cyclamate (as a sodium,potassium or calcium salt), acesulfame-K, thaumatin, neohesperidindihydrochalcone, ammoniated glycyrrhizin, dextrose, levulose, sucrose,mannose, sucralose, stevia, and glucose.

Colorants can be added to improve the aesthetic appearance of theproduct. Suitable colorants include without limitation those colorantsapproved by appropriate regulatory bodies such as the FDA and thoselisted in the European Food and Pharmaceutical Directives and includepigments, such as TiO₂, and colors such as FD&C and D&C dyes.

Preservatives also can be added to the oral care compositions to preventbacterial growth. Suitable preservatives approved for use in oralcompositions such as methylparaben, propylparaben, benzoic acid, andsodium benzoate can be added in safe and effective amounts.

Titanium dioxide may also be added to the present composition. Titaniumdioxide is a white powder which adds opacity to the compositions.Titanium dioxide generally comprises from about 0.25% to about 5%, byweight of the oral care composition.

Other ingredients can be used in the oral care composition, such asdesensitizing agents, healing agents, other caries preventative agents,chelating/sequestering agents, vitamins, amino acids, proteins, otheranti-plaque/anti-calculus agents, opacifiers, antibiotics, anti-enzymes,enzymes, pH control agents, oxidizing agents, antioxidants, and thelike.

EXAMPLES

The invention is further illustrated by the following examples, whichare not to be construed in any way as imposing limitations to the scopeof this invention. Various other aspects, modifications, and equivalentsthereof which, after reading the description herein, may suggestthemselves to one of ordinary skill in the art without departing fromthe spirit of the present invention or the scope of the appended claims.

Experimental Methods

Solubility of Tin Ions at a pH of Greater than 7

A 30% (w/w) solution was prepared for each polyol or combination ofpolyols was prepared using the appropriate amount of the pure polyol anddeionized water. Next, 46 g of the 30% (w/w) polyol solution was placedin a 250 mL glass beaker with a stirring bar on top of a magneticstirring apparatus. 21 g of deionized water was added to the glassbeaker and the magnetic stirring apparatus was started to commencestirring of the solution. A pH electrode was connected to a pH meter(VWR Scientific, Model 9100, Radnor, Pa.) and the pH electrode(ThermoFisher Scientific, Orion 8165BNWP, Waltham, Mass.) was placed inthe stirring polyol solution.

0.45 grams of a tin ion source, such as stannous fluoride, was added tothe stirring polyol solution. The pH was recorded once the tin ionsource was completely added. The pH of the solution was increased bydropwise addition of a 33% (w/w) solution of NaOH.

Solubility of Tin Ions at a pH of Less than 7

A 30% (w/w) solution was prepared for each polyol or combination ofpolyols was prepared using the appropriate amount of the pure polyol anddeionized water. Next, 46 g of the 30% (w/w) polyol solution was placedin a 250 mL glass beaker with a stirring bar on top of a magneticstirring apparatus. 21 g of deionized water was added to the glassbeaker and the magnetic stirring apparatus was started to commencestirring of the solution. A pH electrode was connected to a pH meter(VWR Scientific, Model 9100, Radnor, Pa.) and the pH electrode(ThermoFisher Scientific, Orion 8165BNWP, Waltham, Mass.) was placed inthe stirring polyol solution.

0.45 grams of a tin ion source, such as stannous fluoride, was added tothe stirring polyol solution. The pH was recorded once the tin ionsource was completely added. The pH of the solution was decreased bydropwise addition of a 33% (w/w) solution of HCl.

TABLE 1 Polyol Solutions with SnF₂ Polyol pH 2-4 pH 4-6 pH 6-8 pH 8-10Sorbitol clear cloudy cloudy clear Trehalose (8 OH) clear cloudy cloudycloudy Isomalt (10 OH) clear cloudy cloudy cloudy Sorbitol (6OH):Trehalose clear cloudy cloudy clear (8 OH) (1:1) Sorbitol (6OH):Trehalose clear cloudy cloudy clear (8 OH) (1:3) Sorbitol (6OH):Isomalt clear cloudy cloudy clear (10 OH) (1:1)

TABLE 1 shows the formation of insoluble tin compounds, such as Sn(OH)₂,in the presence of a variety of polyols or combinations of polyols atdifferent pH ranges. A solution that appeared cloudy indicated theformation of insoluble tin complexes. At a pH of greater than 7, acloudy solution indicated the formation of Sn(OH)₂. FIG. 1-6 illustrateTABLE 1 by showing the appearance of each solution described in TABLE 1.

Polyols were screened for their effectiveness at preventing theformation of Sn(OH)₂. For example, an aqueous solution of sorbitol andstannous fluoride, was clear at a pH of from 2 to 4. However, as the pHrose, the solution of sorbitol and stannous fluoride appeared cloudyuntil a pH of from 8 to 10, which appeared clear.

An aqueous solution of trehalose and stannous fluoride, was clear at apH of from 2 to 4. However, as the pH rose, the solution of trehalose orisomalt and stannous fluoride appeared cloudy at every point above pH of4.

A 1:1 or 1:3 mixture of sorbitol and trehalose with stannous fluoride,was clear at a pH of from 2 to 4 and from 8 to 10. Additionally, a 1:1solution of sorbitol and isomalt with stannous fluoride, was clear at apH of from 2 to 4 and from 8 to 10. Thus, the stabilizing polyol canhelp to solubilize the stannous fluoride.

While aqueous solutions of less than 4 were also observed as beingclear, these pH ranges are undesirable because the solubility ofinorganic calcium phosphate compounds, such as hydroxyapatite, isincreased at lower pH conditions. In other words, while stannous can bestable at a pH of 4, tooth enamel can also be solubilized under theseconditions.

Importantly, TABLE 1 surprisingly demonstrates that tin ions can formsoluble complexes with polyols, which prevented the formation ofinsoluble tin compounds, such as Sn(OH)₂ at a high pH. The formation ofinsoluble tin compounds can decrease the tin ion availability, which candecrease the effectiveness of the tin ion source. While not wishing tobe bound by theory, it is believed that sugar alcohols with five or morecarbon atoms, such as xylitol (5 carbon atoms) and/or sorbitol (6 carbonatoms), can form complexes with tin ions, such as stannous, which can besoluble in water-based dentifrice compositions at a pH of greater than7.

Cell Culture

Human gingival epithelial (HGE) cell was maintained in a 37° C.incubator with 5% CO₂ saturation. Dulbecco's modified Eagle's medium(DMEM, Gibco) containing 10% fetal calf serum, 1%penicillin-streptomycin was used as the complete culture medium, whichwas changed every 2-3 days.

Barrier Protection Analysis by Real Time Cell Analyzer (RTCA)

The real time cell analyzer (RTCA) xCELLigence RTCA DP (ACEA BioscienceInc., San Diego, Calif.) equipment, based on impedance measurement, wasused to monitor the barrier protection of polyols. 50 μl completeculture medium was added to E-plates to obtain background readings,followed by the addition of 100 μl of the cell suspension. The E-platescontaining 28000 cell/well were incubated at 37° C., 5% CO₂ for 22-24 huntil cells were confluent. The culture medium was changed to DMEM orDMEM with 1% of polyols, non reducing sugars or combinations andincubated at 37° C., 5% CO₂ for 2 h. The barrier disruptor (capsaicin toa final concentration of 75 μM in this case) was added to wells ofE-plate. Impedance as reflected by the Cell Index (CI) was recordedcontinuously for 16-24 h.

The CI curve was normalized at the time point just before addingpolyols. The normalized CI at 3 h after adding of barrier disruptor wascompared to blank control to generate the percentage of barrier function% comprimisation.

TABLE 2 Barrier Function Treatment Barrier Function Blank 100%  BarrierDisruptor Capsaicin (75 μM) 28% Sorbitol 46% Glycerin 44% Trehalose102%  Isomalt 85% Trehalose:Sorbitol 1:1 81% Trehalose:Sorbitol 3:1 89%

TABLE 2 shows the gum barrier protection benefit provided by one or morepolyols in response to a barrier disruptor. Treatment with the barrierdisruptor (a 75 μM solution of capsaicin) resulted in a barrier functionvalue of 28%. The sugar alcohols sorbitol and glycerin provided amoderate barrier function benefit of 46% and 44%, respectively.Trehalose provided a 102% barrier function benefit. Isomalt provided a85% barrier function benefit. However, neither trehalose nor isomalt wascapable of stabilizing stannous fluoride as shown in TABLE 1 and FIG.1-6.

Importantly, a mixture of trehalose and sorbitol provided an improvedbarrier function (81% at 1:1 or 89% at 3:1). Additionally, the mixtureof trehalose and sorbitol was capable at stabilizing stannous fluorideat a pH of from 8 to 10. Thus, a mixture of a stabilizing polyol and agum strengthening polyol stabilizes tin ions at a pH of from 8 to 10 andprovides a gum barrier protection benefit.

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm.”

Every document cited herein, including any cross referenced or relatedpatent or application and any patent application or patent to which thisapplication claims priority or benefit thereof, is hereby incorporatedherein by reference in its entirety unless expressly excluded orotherwise limited. The citation of any document is not an admission thatit is prior art with respect to any invention disclosed or claimedherein or that it alone, or in any combination with any other referenceor references, teaches, suggests or discloses any such invention.Further, to the extent that any meaning or definition of a term in thisdocument conflicts with any meaning or definition of the same term in adocument incorporated by reference, the meaning or definition assignedto that term in this document shall govern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

What is claimed is:
 1. A dentifrice composition comprising: (a) tin; (b)stabilizing polyol, the stabilizing polyol comprising five or six carbonatoms; (c) gum strengthening polyol, the gum strengthening polyolcomprising seven or more hydroxyl functional groups, and (d) from about10% to about 45%, by weight of the composition, of water, wherein thecomposition has a pH of from 8 to about 10 and wherein the compositionis shelf stable at 23° C. with no formation of Sn(OH)₂.
 2. Thecomposition of claim 1, wherein the composition comprises abrasive. 3.The composition of claim 2, wherein the abrasive comprises silicaabrasive, calcium abrasive, or combinations thereof.
 4. The compositionof claim 3, wherein the composition is essentially free of silicaabrasive.
 5. The composition of claim 3, wherein the calcium abrasivecomprises calcium carbonate, calcium pyrophosphate, or combinationsthereof.
 6. The composition of claim 1, wherein the stabilizing polyolcomprises xylitol, sorbitol, or combinations thereof.
 7. The compositionof claim 1, wherein the gum strengthening polyol comprises trehalose,rafiose, stachyose, verbascose, isomalt, maltitol, lactitol,maltotriitol, maltotetraitol, polyglycitol, or combinations thereof. 8.The composition of claim 1, wherein the composition comprises zinc. 9.The composition of claim 1, wherein the composition comprises from about0.01% to about 15%, by weight of the composition, of one or moresurfactants.
 10. The composition of claim 1, wherein the compositioncomprises thickening agent.
 11. The composition of claim 10, wherein thethickening agent comprises a linear sulfated polysaccharide, a naturalgum, a cellulose derivative, a polyacrylic acid polymer, or combinationsthereof.
 12. The composition of claim 1, wherein the tin comprisesstannous fluoride, stannous chloride, or combinations thereof.
 13. Thecomposition of claim 1, wherein the composition comprises fluoride. 14.The composition of claim 13, wherein the fluoride comprises sodiumfluoride, stannous fluoride, sodium monofluorophosphate, amine fluoride,zinc fluoride, or combinations thereof.
 15. The composition of claims 1,wherein the composition comprises from about 0.01% to about 15%, byweight of the composition, of polyphosphate.